Semiconductor devices in which a semiconductor chip is mounted on a leadframe and encapsulated in resin are known. Because such semiconductor devices generate heat to repeatedly expand and contract during their operations, the semiconductor devices may delaminate at the interface between the leadframe and resin. Therefore, according to such semiconductor devices, the lower surfaces of a die pad and leads are stepped to form stepped parts, and the resin is caused to run around the peripheral edges of the die pad and leads to enter the stepped parts, thereby increasing the adhesion between the resin and the die pads and leads.
Reference may be made to Japanese Laid-open Patent Publication No. 2014-44980 for related art.